Me respondo:
MOODLE dice:
"Lo sentimos, el plugin "mod_chat-phpfreechat" es defectuoso o no actualizado: no se puede continuar."
Debug info: Invalid plugin directory name.
Stack trace:
- line 426 of /lib/upgradelib.php: plugin_defective_exception thrown
- line 265 of /lib/upgradelib.php: call to upgrade_plugins_modules()
- line 1426 of /lib/upgradelib.php: call to upgrade_plugins()
- line 290 of /admin/index.php: call to upgrade_noncore()